Yamaha DRX-1, Руководство по обслуживанию, Страница: 44 / 192

DRX-1
DRX-1
44
Check DC voltages on connector 0205:
Remove all the connectors from the PSU
None of the voltages are present +12Vstby and +5V2stby are OK.
Check +12Vreg circuit:
- D6210, C2210, C2212
Check +Vreg circuit:
- D6240, C2240, C2242
Check Prot_3V3 circuit:
- D6215, C2214, C2215,
- R3520, R3521, D6520
Connect PSU to a mains isolated variac.
Turn the input voltage up and measure
voltage across C2125. Do not exceed
max. mains voltage indicated on player.
This voltage must be +/- 1.41 x Vin AC.
Check +33Vstby circuit:
- D6200, C2200, R3200, D6201, R3201
Check -5Nstby circuit:
- D6220, C2220, IC7220, C2222, C2221
Check FLYB circuit:
- D6221, T7241, R3220, R3221, R3222,
R3223.
Check -Vgnstby circuit:
- D6230, C2230, R3230, D6231, R3233,
R3234, C2235.
Check +12V circuit:
must be present for the other voltages
- Q7511, T7512, D6511, D6512,
- R3511, R3513, R3514, L551, C2512.
Check +3V3 circuit:
- Q7520, Q7521, L5520, C2521, F1520,
- R3522, R3523, R3524, R3525, C2520.
Check +5V circuit:
- Q7501, Q7502, L5501, C2502, R3501
- R3502, R3503, R3504, C2540.
Check +3V3E circuit:
- Q7505, Q7506, D6505, L5505, C2506,
- R3505, R3506, R3507, R3508, C2502.
Check -5V circuit:
- Q7515, D6515, L5515, C2515, R3515.
Standby voltages are oke. Check DC
voltages on connectors 0207 and 0209.
Connector 0207:
+3V3, +5V, -5V, +12V.
Connector 0209:
+3V3, +12V, +5V, -5V, STBY_ctrl.
If not OK, check supply path of failed
supply voltages.
Check primary circuit:
- F1120, D6151, D6152, D6153, D6154,
- R3120, L5120, L5520, C2125.
If fuse 1120 is defective, always check
Q7125, D6145, T7140, Rsense (R3133,
R3134, R3135, R3136 and R3137).
Check with an oscilloscope Vds and Vg
of Q7125.
Is PSU ticking?
Check power switch circuit:
- Q7125, D6130, D3131, D6132
- D6145, D6146, L5125
- C2136
- R3131, R3132, R3133, R3134
- R3135, R3136, R3137, R3146
Check Control circuit
- T7140, D6141, D6142, L5131,
- C2144, C2145, C2147, C2151
- R3151, R3147, R3148, R3150
Check Regulation circuit
- T7251, Q7200, R3250, R3253
- R3254, R3255, R3256, C2251
Check Overvoltage circuit
- T7142, D6143, D6144,
- R3149, R3144, C2152, C2142
Check Overload circuit
- T7141, T7143, R3145, R3143,
- R3142, C2143.
Check start-up circuit:
- R3125, R3126, R3141, R3132
- Q7125, L5131, R3150, C2146
All voltages are present.
+12Vstby, +5V2stby, -5Nstby, -Vgnstby, +33Vstby
NO
YES
If oke, the power supply seems to be ok.
Check the other boards in the player
for the cause of the overload.
Check if STBY_ctrl is LOW.
- Check standby control path via digital
board to analog board.
Fig. 3
2. Power Supply